With over 94 million passenger entries and exits between April 2011 and March 2012, Waterloo is Britain's busiest railway station by passenger usage.[8] The Waterloo complex is the 15th busiest passenger terminal in Europe,[9] and the 91st busiest railway station in the world.[10] It has more platforms and a greater floor area than any other station in the United Kingdom (though Clapham Junction, just under 4 miles (6 km) down the line, has the largest number of trains).

The London and South Western Railway (L&SWR) opened the station on 11 July 1848 as 'Waterloo Bridge Station' (from the nearby Waterloo Bridge over the Thames) when its main line was extended from Nine Elms. The station, designed by William Tite, was raised above marshy ground on a series of arches.[11] The unfulfilled intention was for a through station with services to the City of London. In 1886, it officially became "Waterloo Station", reflecting long-standing common usage, even in some L&SWR timetables.

The L&SWR's aim throughout much of the 19th century was to extend its main line eastward beyond Waterloo into the City of London. Given this, it was reluctant to construct a dedicated grand terminus at Waterloo. However traffic and passenger usage continued to grow and the company expanded the station at regular intervals, with additions being made in 1854, 1860, 1869, 1875, 1878 and 1885. In each case the long-term plan was that the expansion was 'temporary' until Waterloo became through-station, and therefore these additions were simply added alongside and around the existing structure rather than as part of an overall architectural plan.

This resulted in the station becoming increasingly ramshackle. The original 1848 station became known as the 'Central Station' as other platforms were added. The new platform sets were known by nicknames – the two platforms added for suburban services in 1878 were the 'Cyprus Station', whilst the six built in 1885 for use by trains on the Windsor line became the 'Khartoum Station'. Each of these stations-within-a-station had its own booking office, taxi stand and public entrances from the street, as well as often poorly marked and confusing access to the rest of the station.

By 1899 Waterloo had 16 platform roads but only 10 platform numbers due to platforms in different sections of the station or on different levels sometimes duplicating the number of a platform elsewhere.[12] A little-used railway line even crossed the main concourse on the level and passed through an archway in the station building to connect to the South Eastern Railway's smaller station, now Waterloo East, whose tracks lie almost perpendicular to those of Waterloo. Passengers were, not surprisingly, confused by the layout and by the two adjacent stations called 'Waterloo'.

A pair of Class 421 units at Waterloo in 1979; behind them is a Class 487 Driving Motor car, on the site eventually used for Waterloo International

By the late 1890s the L&SWR accepted that main-line access to the City was impossible. In 1898 the company opened the Waterloo & City line, a 'tube' underground railway that ran directly between Waterloo and the City. This gave the company the direct commuter service it had long desired (albeit with the need to change from surface to underground lines at Waterloo). With Waterloo now destined to remain a terminus station, and with the old station becoming a source of increasingly bad will and publicity amongst the travelling public, the L&SWR decided on total rebuilding.

Legal powers to carry out the work were granted in 1899, and extensive groundwork and slum clearance were carried out until 1904, when construction on the terminus proper began. The new station was opened in stages, the first five new platforms opening in 1910. Construction continued sporadically throughout the First World War, and the new station finally opened in 1922 with 21 platforms and a concourse nearly 800 feet (244 m) long. The new station included a large stained glass window depicting the L&SWR's company crest over the main road entrance, surrounded by a frieze listing the counties served by the railway (the latter still survives today). These features were retained in the design despite the fact that by the time the station opened the 1921 Railway Act had been passed which spelt the end of the L&SWR as an independent concern.[13] The main pedestrian entrance, the Victory Arch (known as Exit 5), is a memorial to company staff who were killed during the two world wars. Damage to the station in World War II required considerable repair but entailed no significant changes of layout.

Platforms 20 and 21 were lost to the Waterloo International railway station site, which from November 1994 to November 2007 was the London terminus of Eurostar international trains to Paris and Brussels. Construction necessitated the removal of decorative masonry forming two arches from that side of the station, bearing the legend "Southern Railway". This was re-erected at the private Fawley Hill Museum of Sir William McAlpine, whose company built Waterloo International. Waterloo International closed when the Eurostar service transferred to the new St Pancras railway station with the opening of the second phase of "HS1", High Speed route 1, also known as the Channel Tunnel Rail Link or CTRL. Ownership of the former Waterloo International terminal then passed to BRB (Residuary) Ltd.

The major transport interchange at Waterloo comprises London Waterloo, Waterloo East, the Underground station (which includes the Waterloo and City line to Bank, known informally as 'The Drain'), and several bus stops. There are over 130 automated ticket gates on the station concourse, plus another 27 in the subway below.[17]

Waterloo station connects to Waterloo East railway station, across Waterloo Road, by a high-level walkway, constructed mostly above the previous walkway which used the bridge of the former connecting curve.

Network Rail has constructed a balcony along almost the whole width of the concourse at the first-floor level. The project's aims were to provide 18 new retail spaces and a champagne bar, reduce congestion on the concourse, and improve access to Waterloo East station by providing additional escalators leading to the high-level walkway between Waterloo and Waterloo East. Retail and catering outlets have been removed from the concourse to make more circulation space. First-floor offices have been converted into replacement and additional retail and catering spaces. Work was completed in July 2012, at a cost of £25 million.[19][20][21]

For many years there was a British Transport Police police station at Waterloo by the Victory Arch, with a custody suite of three cells. Although it was relatively cramped, until the late 1990s over 40 police officers operated from it.[22] Following the closure of the Eurostar Terminal at Waterloo,[23] the police station closed in February 2009,[24] and the railway station is now policed from a new Inner London Police Station a few yards from Waterloo at Holmes Terrace.[25] Until July 2010, the Neighbourhood Policing Team for Waterloo consisted of an Inspector, a Sergeant, two Constables, Special Constables, and 13 PCSOs[26] – this establishment was significantly increased by the introduction of the 'Neighbourhood Hub Team' at Waterloo, involving police officers responsible for policing London Underground.

London bus routes 1, 4, 26, 59, 68, 76, 77, 139, 168, 171, 172, 176, 188, 211, 243, 341, 381, 507, 521, RV1, X68 and night buses N1, N68, N76, N171, N343 and N381. Some buses call at stops by the side of the station on Waterloo Road, others at Tenison Way, a short distance from the Victory Arch. These stops replace a former bus station at the lower (Waterloo Road) level where there are now retail outlets and an expanded entrance to the Underground.

The view from the retail balcony towards the north west side of the concourse during rush hour

The main part of the railway station complex is known as "Waterloo Main" or simply Waterloo. This is the London terminus for services towards the south coast and the south-west of England. Waterloo has 19 terminal platforms in use, making it the joint biggest station in the UK in terms of platform numbers with London Victoria. The intention is to bring platform 20 of the former International Station into use as part of Waterloo Main early in 2014. The station is managed by Network Rail, and all regular trains are operated by South West Trains.

Waterloo International was the terminus for Eurostar international trains from 1994 until 2007, when they transferred to new international platforms at St. Pancras. Waterloo International's five platforms were numbered 20 to 24.

The old entrance to Waterloo East from Waterloo, since incorporated into the retail balcony

Adjacent to the main station is a through station called "Waterloo East", the last stop on the South Eastern Main Line towards London before the terminus at Charing Cross. Waterloo East has four platforms, which are lettered rather than numbered to avoid confusion with the numbered platforms in the main station by staff who work at both stations. Waterloo East is managed and branded separately from the main station. Trains go to southeast London, Kent and parts of East Sussex. As of 2008 all regular services are operated by Southeastern (Southern withdrew its services to Charing Cross due to capacity constraints on the South Eastern Main Line west of London Bridge).

In order to increase capacity on South West Trains' overcrowded suburban services into Waterloo, there have for several years been plans to increase train lengths from eight cars to ten. This would require the lengthening of platforms and in particular platforms 1 to 4, which will be a technically complex operation as it will entail a substantial repositioning of track-work and points. SWT also says it would need to have access to at least three of the currently disused international platforms 20 to 24 (see below). Further progress depends on decisions by the Government, and SWT says that until then it cannot proceed with ordering longer trains.[27]

The disused Grimshaw-designed shed of the former Waterloo International can be seen nearer to camera, with the older train shed behind. In the foreground are the Shell Centre (left) and County Hall (right).

Since the transfer of Eurostar services from Waterloo, the former Eurostar platforms 20–24 of Waterloo International have remained unused. Waterloo suffers significant capacity problems, and proposals have been put in place to convert the former international station to domestic use. In December 2008 preparatory work was carried out to enable platform 20 to be used by South West Trains suburban services, including the removal of equipment such as customs control facilities, at an estimated cost of between £50,000 and £100,000.[28] However, the conversion of the remaining platforms was delayed as it would require further alterations to the station infrastructure.

The project has been criticised for its delayed completion date;[29] in 2009 the Department for Transport confirmed that Network Rail was developing High Level Output Specification options for the station, with an estimated date for the re-opening of the platforms of 2014, seven years after their closure.[30]The cost of maintaining the disused platforms up to late 2010 was found via a Freedom of Information request to have been £4.1 million.[27]

In December 2011, South West Trains confirmed that platform 20 will be brought back into use in 2014, hosting certain services to and from Reading, Windsor, Staines and Hounslow. These will be 10-car trains newly formed from refurbished SWT and former Gatwick Express rolling stock.[31] Platform 20 reopened in May 2014, with access via platform 19, and platforms 21 and 22 in October 2014 after steps were constructed over the former Eurostar entrance to access the platforms.[32][33]

From 4 July 2010 to 2 January 2011, two of the disused platforms hosted a theatrical performance of The Railway Children by E. Nesbit. The audience was seated either side of the actual railway track. The show included the use of a steam locomotive coupled to one of the original carriages from the 1970s film (propelled by a diesel locomotive). The performance moved to London after two acclaimed summer runs at the National Railway Museum in York.[34]

Waterloo station was to be the central London terminus for the proposed Heathrow Airtrack rail service. This project, promoted by BAA, envisaged the construction of a spur from Staines on the Waterloo to Reading Line to Heathrow Airport, creating direct rail links from the airport to Waterloo, Woking and Guildford. Airtrack was planned to open in 2015, but was abandoned by BAA during 2011.[35] However in October 2011 Wandsworth Council proposed a revised plan called Airtrack-Lite, which would provide trains from Waterloo to Heathrow via the same proposed spur from Staines to Heathrow, but by diverting or splitting current services the frequency of trains over the existing level crossings would not increase. BAA's earlier plan had controversially proposed more trains over the level crossings, leading to concerns that they would be closed to motorists and pedestrians for too long.[36]

The station took its name from the nearby Waterloo Bridge, which was in turn named after the Battle of Waterloo, a battle that occurred exactly two years prior to the opening ceremony for the bridge.[38][39]

In the 1990s, after Waterloo station was chosen as the British terminus for the Eurostar train service, Florent Longuepée, a municipal councillor in Paris, wrote to the British Prime Minister requesting that the station be renamed because he said it was upsetting for the French to be reminded of Napoleon's defeat when they arrived in London by Eurostar.[40] There is a name counterpart in Paris: the Gare d'Austerlitz is named after the Battle of Austerlitz, one of Napoleon's greatest victories (over the Russians and Austrians).

Two of the most famous images of the station are the two Southern Railway posters "Waterloo Station – War" and "Waterloo Station – Peace", painted by Helen McKie for the 1948 centenary of the station. The two pictures show hundreds of busy travellers all in exactly the same positions and poses, but with altered clothing and roles. The preparatory sketches for these were drawn between 1939 and 1942.[41]

In 1981, Shell UK commissioned a work of art to be exhibited above the Shell exit on a poster site which had been acquired from Esso, Shell’s great rival. The massive canvas measured 26 ft long x10 ft high. The artist commissioned to paint the mural was Jane Boyd,[42] a recent graduate from Camberwell College of Arts. The work, entitled The Generation of Alternatives, was selected by a panel of judges comprising artists David Gentleman, John Piper and Gillian Ayres and it was viewed during execution and for a further six months by the quarter of a million people who passed through London Waterloo Station everyday – including several thousand Shell UK staff, bound for Shell Centre and Shell Mex House through what was known as the Shell Exit. One important element of the project was said by commission organiser John Collyer to be "the pleasure and interest enjoyed by Waterloo commuters as the painting was created before their eyes. Having acquired the site we wanted a project to intrigue and entertain. A mural being painted above travellers’ head seem to fit the bill”.[43]

In Jerome K Jerome's 1889 comic novel, Three Men in a Boat, the protagonists spend some time in the station, trying to find their train to Kingston upon Thames. After being given contradictory information by every railway employee they speak to, they eventually bribe a train driver to take his train to their destination:

We got to Waterloo at eleven, and asked where the eleven-five started from. Of course nobody knew; nobody at Waterloo ever does know where a train is going to start from, or where a train when it does start is going to, or anything about it. The porter who took our things thought it would go from number two platform, while another porter, with whom he discussed the question, had heard a rumour that it would go from number one. The station-master, on the other hand, was convinced it would start from the local.[46]

In Robert Louis Stevenson & Lloyd Osbourne's 1889 novel The Wrong Box, much of the farcical plot revolves around the misdelivery of two boxes at Waterloo station, and the attempts by the various protagonists to retrieve them. This description of the station on Sunday is from the novel:

About twenty minutes after two, on this eventful day, the vast and gloomy shed of Waterloo lay, like the temple of a dead religion, silent and deserted. Here and there at one of the platforms, a train lay becalmed; here and there a wandering footfall echoed; the cab-horses outside stamped with startling reverberations on the stones; or from the neighbouring wilderness of railway an engine snorted forth a whistle. The main-line departure platform slumbered like the rest; the booking-hutches closed; the backs of Mr Haggard's novels, with which upon a weekday the bookstall shines emblazoned, discreetly hidden behind dingy shutters; the rare officials, undisguisedly somnambulant; and the customary loiterers, even to the middle-aged woman with the ulster and the handbag, fled to more congenial scenes. As in the inmost dells of some small tropic island the throbbing of the ocean lingers, so here a faint pervading hum and trepidation told in every corner of surrounding London.

In H. G. Wells' famous 1897 science fiction novel, the War of the Worlds, the little used, and long since vanished, connecting track across the station concourse to Waterloo East station makes an appearance:

About five o'clock the gathering crowd in the station was immensely excited by the opening of the line of communication, which is almost invariably closed, between the South-Eastern and the South-Western stations, and the passage of carriage trucks bearing huge guns and carriages crammed with soldiers. These were the guns that were brought up from Woolwich and Chatham to cover Kingston. There was an exchange of pleasantries: "You'll get eaten!" "We're the beast-tamers!" and so forth. A little while after that a squad of police came into the station and began to clear the public off the platforms, and my brother went out into the street again.[47]

^"The Opening of Waterloo Bridge". Retrieved 9 November 2010. "The first Waterloo Bridge, designed by John Rennie, was opened by the Prince Regent amid much pageantry on 18 June 1817, the second anniversary of the battle it commemorated.")